Semiconductor devices based on silicon carbide (SiC) can be designed with lower on-resistance and higher breakdown voltage than semiconductor devices based on silicon (Si). SiC-based semiconductor devices have negative temperature characteristic in which the on-resistance decreases with the increase of temperature. Thus, in the case of using the device with a large current passed therein, an excessive current flows in the semiconductor device. In SiC-based semiconductor devices, it is important to achieve stable characteristics against the change of temperature.